Anesthesia lidocaine

Presentation Transient radicular irritation causes transient pain in the back, buttocks, and lower extremities, without formal neurological signs or symptoms. It can follow single-dose intrathecal anesthesia. Lidocaine has been reported as the predominant culprit. However, transient radicular irritation has also been reported with bupivacaine, mepivacaine, tetracaine, and prilocaine. Osmolarity, the addition of dextrose, and speed of injection do not contribute, and even reducing the concentration of hdocaine does not alter the incidence (220,221). 

Menendez-Botet, C. J., Collin, C., Osborne, M., Rosen, P., and Schwartz, M. K., Effect of local anesthesia (Lidocaine) and saline on the estrogen and progesterone receptor protein in breast tissue. Clin. Chem. (Winston-Salem, N.C.) 30, 941 (1984). 

For intravenous regional anesthesia, lidocaine is administered in 0.5% solution. For peripheral neural blockade, the 2% solution with or without epinephrine is most commonly administered to provide fastest onset of action as well as maximal surgical motor blockade. More dilute concentrations such as 1-1.5% may also be administered, but provide less motor blockade than the 2% solution. 

Lidocaine hydrochloride [73-78-9] (Xylocaine), is the most versatile local anesthetic agent because of its moderate potency and duration of action, rapid onset, topical activity, and low toxicity. Its main indications are for infiltration, peripheral nerve blocks, extradural anesthesia, and in spinal anesthesia where a duration of 30 to 60 min is desirable. Because of its vasodilator activity, addition of the vasoconstrictor, epinephrine, increases the duration of action of Hdocaine markedly. It is also available in ointment or aerosol preparations for a variety of topical appHcations. 

The primary site of action of epidurally administered agents is on the spinal nerve roots. As with spinal anesthesia, the choice of drug to be used is determined primarily by the duration of anesthesia desired. However, when a catheter has been placed, short-acting drugs can be administered repeatedly. Bupivacaine is typically used when a long duration of surgical block is needed. Lidocaine is used most often for intermediate length procedures chloroprocaine is used when only a very short duration of anesthesia is required. 

Similar to Voltaren" Emulgel, oily droplets of an eutectic mixture of lidocaine and prilocaine are dispersed in a hydrogel to provide local anesthesia to the skin for injections and siugical treatment (Emla cream). A further possibility is the dermal administration of a liposome dispersion as a spray (Heparin PUR ratiopharm Spriih-gel "). After administration, water and isopropylic alcohol evaporate partially resulting in an increase of concentration and in a transition from the initial liposome dispersion into a lamellar liquid crystal [32]. The therapeutic effect appears to be influenced favorably by the presence of lecithins rather than by the degree of liposome dispersion. 

Other agents employed for surface anesthesia include the uncharged poli-docanol and the catamphiphilic cocaine, tetracaine, and lidocaine. 

Spinal anesthesia Spinal anesthesia is the introduction of local anesthetics directly into the spinal fluid, which causes a sympathetic blockage, or loss of feeling as well as muscle relaxation resulting from the interaction of anesthetic with every spinal nerve tract. This method is used during major surgical interventions. As a rule, lidocaine, mepivacaine, and bupivacaine are used for this purpose. 

Epidural anesthesia This term is understood to be an introduction of local anesthetic into the spinal cord membrane of the intervertebral space. It is used during obstetrical and gynecological interventions that do not require a fast development of anesthesia. Drugs such as lidocaine, mepivacaine, bupivacaine, ethidocaine, and chloroprocaine are used for this purpose. 

Lidocaine is the most widely used local anesthetic. Its excellent therapeutic activity is fast-acting and lasts sufficiently long to make it suitable for practically any clinical use. It stabilizes cell membranes, blocks sodium channels, facilitates the secretion of potassium ions out of the cell, and speeds up the repolarization process in the cell membrane. It is used for terminal infiltration, block, epidural, and spinal anesthesia during operational interventions in dentistry, otolaryngology, obstetrics, and gynecology. It is also used for premature ventricular extrasystole and tachycardia, especially in the acute phase of cardiac infarction. Synonyms for this drug are xylocaine, neflurane, and many others. 

Amide-type agents include articaine, lidocaine, bupivacaine, prilocaine, mepivacain and ropiva-caine. These are metabolized in the liver by microsomal enzymes with amidase activity. The amide group is preferred for parenteral and local use. If by accident rapidly administered intravascularly these agents, especially bupivacaine but also lidocaine, can produce serious and potentially lethal adverse effects including convulsions and cardiac arrest. They can more easily accumulate after multiple administrations. Intravenous lidocaine is sometimes used for regional anesthesia, for infiltration procedures, for the induction of nerve blockade and for epidural anesthesia. However, it is also used as an antiarrhythmic. Bupivacaine is a long-acting local anesthetic used for peripheral nerve blocks and epidural anesthesia. 

Phenytoin, like lidocaine, is more effective in the treatment of ventricular than supraventricular arrhythmias. It is particularly effective in treating ventricular arrhythmias associated with digitalis toxicity, acute myocardial infarction, open-heart surgery, anesthesia, cardiac catheterization, cardioversion, and angiographic studies. 

Lidocaine hydrochloride Xylocaine) is the most commonly used local anesthetic. It is well tolerated, and in addition to its use in infiltration and regional nerve blocks, it is commonly used for spinal and topical anesthesia and as an antiarrhythmic agent (see Chapter 16). Lidocaine has a more rapidly occurring, more intense, and more prolonged duration of action than does procaine. 

EMLA cream (lidocaine 2.5% and prilocaine 2.5%) consists of a eutectic mixture of focal anesthetics. It is used to provide topical anesthetic to intact skin. Other topical preparations are effective only on mucosal surfaces. EMLA has been shown to reduce pain on venipuncture and provide substantial anesthesia for skin graft donor sites. No significant local or systemic toxicity has been demonstrated. 

Answer Bupivacaine use for local anesthesia of this type is very safe and commonly done. However, SOMETIMES inadvertent vascular injection results in a large amount of anesthetic in the systemic circulation. Because the heart is beating, the excitable tissue in the heart is being depolarized repetitively. Local anesthetics bind to rapidly depolarizing tissues more than tissues at rest (frequency-dependent block). Also, bupivacaine has a long duration of action because of its long residence time at receptors (sodium channel). Thus, this combination of factors contributed to the catastrophic outcome of this case. Had the same case involved lidocaine, the resuscitation would have likely been successful. 

Previously used as component of "Magic Numbing Solution" or TAC Sol (epinephrine 1 2,000, tetracaine 0.5%, cocaine 11.8%) and LET Sol (lidocaine 4%, epinephrine 0.1%, tetracaine 0.5%), which are used as topical anesthesia for repair of minor lacerations. Topical tetracain solutions no longer available... 

Several first-generation Hi antagonists are potent local anesthetics. They block sodium channels in excitable membranes in the same fashion as procaine and lidocaine. Diphenhydramine and promethazine are actually more potent than procaine as local anesthetics. They are occasionally used to produce local anesthesia in patients allergic to conventional local anesthetic drugs. A small number of these agents also block potassium channels this action is discussed below (see Toxicity). 

Although other drugs such as lidocaine have been recommended for the treatment of generalized tonic-clonic status epilepticus, general anesthesia is usually necessary in highly resistant cases. 

Topical local anesthesia is often used for eye, ear, nose, and throat procedures. Satisfactory topical local anesthesia requires an agent capable of rapid penetration across the skin or mucosa, and with limited tendency to diffuse away from the site of application. Cocaine, because of its excellent penetration and local vasoconstrictor effects, has been used extensively for ear, nose and throat (ENT) procedures. Cocaine is somewhat irritating and is therefore less popular for ophthalmic procedures. Recent concern about its potential cardiotoxicity when combined with epinephrine has led most otolaryngology surgeons to switch to a combination containing lidocaine and epinephrine. Other drugs used for topical anesthesia include lidocaine-bupivacaine combinations, tetracaine, pramoxine, dibucaine, benzocaine, and dyclonine. 

Lidocaine Blockade of sodium channels Slows, then blocks action potential propagation Short-duration procedures epidural, spinal anesthesia Parenteral duration 30-60 min 2-6 h with epinephrine Toxicity CNS excitation... 

When tolerability of the compound is sufficient to allow systemic administration, local anesthetic drugs can be employed for relief of neuropathic pain and acute treatment of migraine headache in addition to the broad application for local anesthesia as proven for lidocaine... 

Lidocaine is the most commonly used local anesthetic drug. In addition to its effectiveness for local anesthesia, it provides relief of neuropathic pain and acute migraine headache... 

In addition to its use for anesthesia and analgesia, lidocaine is also used for acute treatment of ventricular arrhythmias. 

Clinical use Mepivacaine has been employed for all types of infiltration and conduction nerve block anesthesia using solutions of 1.0 and 1.5 % lasting for 1.5 to 3 h. Epidural anesthesia with 2.0 % mepivacaine has a rapid onset with a dense motor block. Hyperbaric solutions of mepivacaine have also been used for spinal anesthesia (Tetzlaff, 2000). Mepivacaine has been used for topical applications, but other LA such as lidocaine are more effective. 

Clinical use Topical anesthesia is easily achieved using an eutectic mixture of the LAs prilocaine and lidocaine (EMLA, see Lidocaine). 

Clinical use Because of its poor penetration of intact mucous membranes, procaine is largely ineffective for topical applications and has been mainly used in injection in combination with adrenaline, although in general it has been replaced by other LAs such as lidocaine. For infiltration anesthesia, 0.25 to 0.5 % solutions of procaine have been used in doses up to 600 mg. For peripheral nerve block, a common dose of 500 mg of procaine has been given as a 0.5 to 2.0 % solution. 

Clinical use Tetracaine is employed by ophthalmologists for surface anesthesia as a 0.5 % solution and by endoscopists for anesthesia of mucous membranes including airways as a 2.0 % solution. For topical anesthesia, a 4.0 % cream of tetracaine can also be used, which is, however, less effective than a lidocaine/prilocaine cream in preventing venipuncture-induced pain in children (van Kan et al., 1997). A combination of tetracaine with adrenaline and cocaine (TAC) is widely used for repair of... 

Zempsky, W.T., et al. 2004. Evaluation of a low-dose lidocaine iontophoresis system for topical anesthesia in adults and children A randomized, controlled trial. Clin Ther 26 1110. 

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